Mixing valve construction, system and method

ABSTRACT

This application discloses a valve construction having a modulating pilot diaphragm fluid control which cooperates with an adjustable pilot which remains stationary after adjustment to control the flow of the fluid. This valve construction may be used in a construction having a hot water inlet, a cold water inlet, a mixing chamber connected to said cold water inlet and said hot water inlet, a hot and mixed water outlet connected to said mixing chamber, and a variable flow control construction controlling the flow of cold water from said cold water inlet to said mixing chamber. This variable flow control construction may be a modulating control construction, so that the water flow from the cold water inlet may be modulated to the desired volume to produce the desired mixture of hot and cold water at the mixed water outlet. Other fluids, instead of hot and cold water, may be controlled and mixed by the valve construction. More than two fluids may enter more than two inlets in the valve construction. A flexible variable orifice means may be used adjacent one or more of the inlets. The valve construction may be unitary or homogeneous, such as a casting.

United States Patent [72] Inventors Harold A. McIntosh South Pasadena;Gordon K. Slocum, Downey, both of Calif. [21] Appl. No. 18,362 [22]Filed Feb. 26, 1970 [45] Patented Oct. 5, 1971 [73] Assignee RobertsbawControls Company Richmond, Va. Continuation of application Ser. No.716,557, Mar. 27, 1968, now abandoned.

[54] MIXING VALVE CONSTRUCTION, SYSTEM AND METHOD 5 Claims, 22 DrawingFigs.

[52] US. Cl 137/606, 137/334,137/525.l, 236/12 A, 251/38, 251/DIG. 3

[51] Int. Cl Fl6k 19/00 [50] Field of Search 137/334, 337, 605, 606,607; 251/38, DIG. 3; 236/12 A [56] References Cited UNITED STATESPATENTS 804,650 11/1905 Crane 251/38 854,138 5/1907 Backus, Jr. et al...251/38 2,528,422 10/1950 Chace 251/38X 2,604,905 7/1952 Myer..... 251/382,758,610 8/ l956 I-l iv ely 137/605 2,823,695 2/1958 Coffin 7 137/3373,021,868 2/1962 Kovach 137/337 X FOREIGN PATENTS 1,258,968 3/1961France 236/12 A 5,502 12/1880 Great Britain 25l/D1G. 3 937,537 9/1963Great Britain 236/12 A Primary Examiner- Robert G. NilsonAttorneys-Auzville Jackson, Jr., Robert L. Marben and Candor, Candor &Tassone ABSTRACT: This application discloses a valve construction havinga modulating pilot diaphragm fluid control which cooperates with anadjustable pilot which remains stationary after adjustment to controlthe flow of the fluid. This valve construction may-be used in aconstruction having a hot water inlet, a cold water inlet, a mixingchamber connected to said cold water inlet and said hot water inlet, ahot and mixed water outlet connected to said mixing chamber, and avariable flow control construction controlling the flow of cold waterfrom said cold water inlet to said mixing chamber. This variable flowcontrol construction may be a modulating control construction, so thatthe water flow from the cold water inlet may be modulated to the desiredvolume to produce the desired mixture of hot and cold water at the mixedwater outlet. Other fluids, instead of hot and cold water, may becontrolled and mixed by the valve construction. More than two fluids mayenter more than two inlets in the valve construction. A fleiiblevariable orifice means may be used adjacent one or more of the inlets.The valve construction may be unitary or homogeneous, such as a casting.

PATENTED UBT 5|97i SHEET 1 OF 4 2 Amm MU 7 6 l F O 8 4 .l I 6 m 55 6HAROLD A. MclNTOSH GORDON FIG-l3 6O FIG-2 PATENTED OCT 5 I97! sum 3 0r 4FlG-l6 FIG-l8 INVENTORS |64 ies HAROLD A. MCINTOSH GORDON K. SLOCUMTHEIR ATTORNEYS PATENTED mm 5197: I 3.610279 ISA 42 42A 4 64A g4 32A 32INVENTORS |3A HAROLD A. MclNTOSH BY GORDON K. SLOCUM THEIR ATTORNEYSMIXING VALVE CONSTRUCTION, SYSTEM AND METHOD This application is acontinuation of application Ser. No. 7 I 6,557, filed Mar. 27, 1968 nowabandoned.

This invention relates to a fluid-mixing valve construction, system andmethod.

A feature of this invention, includes a variable orifice means to beused where desired, such as in any of the fluid inlet means to bedescribed.

Another feature of this invention includes a valve construction having amodulating pilot diaphragm fluid control which cooperates with anadjustable pilot which remains stationary after adjustment to controlthe flow of the fluid.

Another of the features of this invention includes a fluid flow valveconstruction, system and method including a first fluid inlet means, asecond fluid inlet means, a fluid-mixing means connected to said firstfluid inlet means and to said second fluid inlet means, a first fluidand a mixed fluid outlet means connected to said mixing means, andvariable control means controlling the flow of said second fluid throughsaid second fluid inlet to said mixing means.

Another feature of this invention includes the control of hot water asthe first fluid, and of cold water as the second fluid in theconstruction of the above feature.

More than two fluid inlet means with one or more variable orifice meansmay be provided for the mixing means.

Other features of this invention are apparent from this description, theappended claimed subject matter, and/or the accompanying drawing inwhich:

FIG. I is a diagrammatic illustration of a fluid or water flow system ofthis invention.

FIG. 2 is an exploded diagrammatic view of the mixing valve constructionshown in FIG. 1.

FIG. 3 is a diagrammatic cross section of the fluid flow valve of FIG.1, taken along the line 33 of FIG. 1.

FIG. 4 is a cross section along the line 4-4 of FIG. 3.

FIG. 5 is a cross section along the line 5-5 of FIG. 3.

FIG. 6 is a detailed view of the lower end of the actuator or controlrod shown in FIG. 3.

FIG. 7 is an end view along the line 7-7 of FIG. 6.

FIG. 8 is a cross section of a modified cold water inlet orifice.

FIG. 9 is a plan view of a typical hot water variable orificeconstruction using six radial slits, which may be used in FIGS. 3-5.

FIG. 10 is a combined perspective view and cross section along the lineI0 10 of FIG. 9.

FIG. 11 is a plan view of a retaining ring for the variable orificeconstruction.

FIG. 12 is a cross section along the line 12-12 of FIG. 11.

FIG. 13 is a plan view of another form of variable orifice, using onlyfour radial slits, as shown in FIG. 4.

FIG. 14 is a plan view of another modified variable orifice.

FIG. 15-18 show cross sections of other embodiments of the variableorifice.

FIG. 19 shows another construction for adjusting the control lever.

FIG. 20 shows a valve construction with more than two inlets.

FIG. 21 is an enlarged cross section taken along line 2I-21 of FIG. 20.

FIG. 22 shows another application of the variable orifice means.

This invention may be used in connection with the control of the flowand mixing of fluids, whether such fluids are gaseous or liquid. Aresilient variable orifice means may be used in the inlet means of avalve construction. Such valve construction may be relatively small,such as is used in buildings such as houses, apartments. and the like,or it may be of relatively large size, such as for commercial andindustrial types of buildings.

The invention, including the variable orifice means will be describedspecifically in connection with a valve construction with hot and coldwater as the fluids being controlled, but it is to be understood thatother constructions and other fluids may be controlled and such fluidsmay be gaseous and/or liquid, as desired.

Referring to the drawings, this invention may include a fluid mixingvalve construction or means 9 through which a first fluid, such as hotwater, enters at a first fluid or hot water inlet means 10, and passesthrough a first fluid and second fluid, or hot and cold water mixingchamber or means 11, where the hot water can be mixed with cold water.From there the hot water alone, or mixed with cold water, can bedischarged through a first fluid or hot water or a mixed fluid or mixedhot and cold water outlet means 12. The second fluid or cold water mayenter through a second fluid or cold water inlet means 13, flow througha second fluid or cold water varying or modulating valve construction ormeans 14 into the mixing chamber 11. The modulating valve construction14 may include a diaphragm means 15 and a regulating pilot plunger means16 which may be adjusted toward and away from the diaphragm 15 toregulate or modulate the flow of cold water into the mixing chamber 11.The construction is such that the adjustment of the plunger 16 governsthe ratio of hot and cold water which is discharged at the mixed wateroutlet 12.

While the valve construction 9 thus far described is of great advantage,a further improvement may be obtained by providing a variable orificemember or means 17 in the hot water inlet 10. This member 17 isresponsive to the volume of flow of the hot water in inlet means 10 sothat its effective orifice 18 decreases in water flow resistance when arelatively large volume of hot water passes such orifice l8 andincreases its water flow resistance when in a relatively small volume ofhot water passes the orifice 18. This variation of resistance may beobtained by constructing the orifice member 17 so that the orifice 18increases in size and decreases in resistance when such relatively largevolume of hot water passes the orifice 18 and decreases in size andincreases in resistance when said relatively small volume of hot waterpasses such orifice 18. In the embodiment shown in FIGS. l-I3, theorifice member 17 is a flexible or resilient disc that flexes orotherwise changes in response to hot water flow to obtain such orificesize variation. The word flexible" when hereafter used is intended to beused as "resilient."

The valve construction 9 with the cold water modulating valveconstruction 14 and the hot water variable flow resisting orifice member17 is of particular advantage when used for mixing fluids, such as hotand cold water, from the inlets l0 and 13 which have substantially equalpressures at such inlets l0 and 13 but have different characteristics,such as different temperatures, at such hot and cold water inlets I0 and13. This advantage occurs particularly when the hot water and mixed hotand cold water outlet 12 is connected to a volume flow regulatingdischarge valve 19 which may regulate the volume of hot water and mixedcold and hot water leaving the mixing chamber I lthrough such wateroutlet 12.

In a valve construction 9 that is not provided with the variable orificemember 17, the ratio of hot and cold water leaving the mixed outletl2varies when the volume of flow is varied by changing the valve openingor flow rate of discharge valve 19. It has been found that when asmaller volume of flow is selected at valve 19, by turning handle 20,the temperature of the mixture rises materially and when a larger volumeis selected at valve 19 the mixture temperature falls materially. Thishappens even if the hot water and cold water pressures at theirrespective inlets l0 and 13 remain equal and their respectivetemperatures remain unchanged, and while the modulating valveconstruction 14 also is unchanged.

These conditions prevail in the usual hot and cold water systems inbuildings, such as houses, apartments, and commercial buildings and thelike.

For example, such buildings may be provided with a cold water supplymain source or pipe 21 which may be directly or indirectly connected toall of the cold water pipes or branches of the building, and suppliessuch pipes or branches with cold water of a generally constanttemperature, particularly when such water has been run off at thevarious faucets to obtain such generally constant or satisfactoryconstant cold water temperature, within reasonable limits, as is wellknown and expected. Such cold water supply 21 may be connected as shownto any well known heating means or water heater 22, which may bethermostatically controlled if desired, to maintain the hot waterleaving in the hot water pipe 23 at a generally constant hot watertemperature with certain immaterial variations within reasonable limits.This hot water from pipe 23 may be distributed to various hot waterpipes or branches of the building which, in turn, are connected tovarious hot water discharge valves and faucets.

According to this invention, one of these hot water pipes or branches 24may be connected to the hot water inlet of the mixing valve construction9, and one of the cold water branches 25 may be connected to the coldwater inlet 13 of the mixing valve construction 9. The hot or mixed hotand cold water outlet 12 may be connected to pipe 26 and indirectly todischarge valve 19, which may be connected to a discharge faucet 27 byconnection 28.

The mixing valve construction 9 is such that the user may adjust themodulating rod 29 to adjust the plunger 16 and action of diaphragm sothat the water discharged through the pipe 26, valve 19 and faucet 27 isall hot water from hot water pipe 23 by adjusting the upper end of rod29 rightwardly in direction 30, to an all hot position which closes thediaphragm 15 completely against the cold water inlet or valve seatorifice wall 31, as more fully elsewhere described.

The user may select to have a mixture of hot and cold water mixed atmixing chamber 11 and delivered at valve 19 and faucet 27. This isaccomplished by adjusting the upper end of rod 29 leftwardly or indirection 30' to reduce the mixed water temperature by increasing theamount of cold water that enters into valve seat orifice wall 31 andcold water passageway 32 into mixing chamber 1 1. Thus modulation of theupper end of rod 29 in arrow direction 30' decreases the temperature ofthe mixed water at outlet 12 and faucet 27 and modulation of the rod 29in arrow direction 30 increases the mixed water temperature. Modulationof rod 29 to the farthest position in direction 30 closes the diaphragm15 against valve seat 31 and prevents any cold water from entering themixing chamber 11, so that only hot water can flow from hot water inlet10 to outlet l2 and faucet 27.

if desired, an all cold water valve 33 may be provided which may beopened and closed by knob or handle 34 and which is connected by coldwater branch pipe 35 to the cold water supply 21.

The water discharge fixture 36 may be any desired type of waterdischarge fixture. As shown in FIG. 1, the valves 19 and 33 may beconnected by connections 28 and 37 with the common discharge faucet 27.Such fixture 36 may be any wellknown fixture of this type. However, thefixture 36 may be of any other well-known type, such as a shower head,or a fixture having separate faucets for valves 19 and 33, or any otherfluid discharging fixture or construction, as desired.

The fluid flow or valve construction 9 may include a unitary orhomogeneous valve casing of any desired material in which there isprovided with cylindraceous hot water inlet wall 10, and thecylindraceous mixing chamber wall 38 connected and aligned with said hotwater inlet wall 10. The cylindraceous mixed water outlet wall 12 isconnected to and aligned with said mixing chamber wall 38. Thecylindraceous cold water inlet wall 13 may be perpendicular to andsupported by the mixing chamber wall 38. The fixed cold water diaphragmseat orifice wall 31 is formed in the mixing chamber wall 38 and isconnected in cold water flow relationship by cold water passageway 39 tothe said cold water inlet wall 13 and to the mixing chamber 11 and wall38 by passageway 32. The said diaphragm seat orifice wall 31 may besurrounded by a diaphragm support wall 40. Such walls 31 and 40 may beintegrally or homogeneously formed together and may be a part of chamberwall 38.

The diaphragm 15 may have a pilot opening construction 42 and a bleedopening construction 44.

A pilot chamber means 46 sealingly holds the diaphragm 15 on thediaphragm support wall construction 40 by means of its rim 48. The pilotplunger or plunger means 16 is reciprocable in the pilot chamber means46 toward and away from the pilot opening construction 42 to modulatethe flow of cold water through the fixed orifice wall 31 and thusmodulate the ratio of mixture of cold water with hot water which entersthe mixing chamber 11 and is discharged as mixed water or only hot waterthrough the outlet 12.

The said pilot chamber means 46 may be a cylindraceous diaphragmengaging sealing wall, which has a rim 48 for holding the diaphragm 15against the diaphragm support wall 40.

The pilot chamber means 46 has a pilot plunger bearing means 50 in whichthe pilot means 16 reciprocates back and forth.

The hot water inlet wall 10 may be provided with the variable hot waterorifice construction 17, or 17A or 178. Such orifice construction may bea resilient member or rubber disc 17 which may be held at the rim 52 onone side of the disc 17 by the backing member or ring 54, which may beprovided with a rounded backing wall 56. The rubber disc 17 may be heldin place on the other side by an outwardly biased split C-ring 58 whichis expanded in a suitable groove to receive the same as shown.

The resilient member 17 may have a plurality of radial slits 60, whichpermit the resilient member 17 to yield to the downstream flow of hotwater, as illustrated in FIG. 3, to provide a variable orifice 18, asillustrated in FIGS. 3 and 4. The tongues 62 between the radial slits 60bulge upwardly, as shown in FIGS. 3 and 4, so that the orifice 18enlarges as the valve 19 is opened wider to decrease the resistance tothe flow of hot water into the mixing chamber 11 as compared to theresistance when the valve 19 is not widely opened.

The mixing chamber wall 38 is inwardly bulged to make the mixing chambernarrower than the inner diameter of the inlet 10 or outlet 12 or theinner diameter of the pipes 24 and 26. This also tends to create asuction action on the cold water passageway 32 to induce the flow ofcold water from cold water inlet 13 into mixing chamber 11 in spite ofthe substantially equal pressures of the hot and cold water in hot waterpipe 24 and cold water pipe 25.

The plunger 16 has a pointed reduced size end piece 64 which cooperateswith the pilot opening construction 42 and the bleed opening 44 so thatsubstantially no longitudinally thrust is placed on the plunger 16. Theplunger 16 may be hexagonally cross sectioned with an actuating slit orgroove 66. A rod cavity 68 is provided for the lower end of rod 29 whichis flexibly sealed by seal 70. The rod 29 is provided with a stationarypin or fulcrum 72 which is carried by a washer 71 at the lower end ofthe hollow externally threaded nut 74. The end of nut 74 seals thewasher 71 against the rim of flexible seal 70.

The plunger 16 has two round plunger bearings 76 and 78 on each side ofthe rod 29 and groove 66 to allow the pressure to equalize at each endof the plunger 16. The rod 29 has a fork 80 with two inward relativelysharp edges 82 which enter the groove 66 of plunger 16.

The construction is such that there is substantially no end thrust onthe plunger 16 and there is practically no turning force produced byplunger 16 on the lower end of the rod 29, about the fulcrum 72. Thereis substantially no manipulation force required for rod 29 in thedirections 30 and 30. The rod tends to remain where placed.

If desired, an actuation means or rod 84 may hingedly be secured to rod29 and which passes through a stationary block 86 with a slightfrictional resistance. This will maintain the rod 29 in the positionselected by the user. Alternatively the rectangle 86 may represent anyactuating mechanism which is to move and maintain the end of the rod 29at any desired location. Such actuating mechanism may be a thermostatic,mechanical, electrical, vacuum or other suitable means. It can be amanually adjustable thermostatic mechanisms powered by a thermostaticbulb 87 located in the outlet end of mixing chamber 1 1, to maintain themixed fluid at a selected substantially constant temperature.

The pointed end piece 64 of the adjustable plunger means 16 may beadjusted by the adjustment means or rod 29 to the desired position,there to remain stationary while the diaphragm l5 and its pilot opening42 are held spaced from the valve seat means 31 the desired distance topermit the proper flow of fluid, such as cold water, past the valve seat31 into the passageway 32 and into the mixing chamber 11. If desired,the pilot opening 42 may have a funnel-shaped right end, FIG. 3. Theconstruction is such that it induces proper cooperation of the pressureson each side of the diaphragm 15 by reason of the pilot opening 42 andbleed opening 44 to obtain a constant or modulated fluid flow into theorifice valve seat 31.

FIG. 8 shows a valve seat orifice wall 31A which is substantiallyparallel to the plane of the diaphragm support wall. The embodiment ofFIG. 8 may be substituted in FIGS. 3 and 4 in an obvious manner.

The advantage of the resilient variable orifice member 17 or 17A is thatit tends to neutralize the variation of the hot water and cold waterratio which occurs when the flow volume is varied at the discharge meansor discharge valve 19 and faucet 27. The variable orifice 18 or 18Acauses the desired ratio of hot or cold water to be maintained much moreclosely than is possible with the use of an invariable orifice (notshown which also may be used instead of the variable orifice means 17.

The variable orifices l7 and 17A very materially reduce the mixtemperature change as the volume at discharge valve 19 is varied, ascompared by a fixed orifice in the place of the variable orifice. Thediscs 17 and 17A may be made of any suitable rubberlike material and maybe, for example, 0.875 inches outside diameter. The radial slits 60 and60A may have an outside diameter of 0.625 inches. The discs may be 0.063inches thick. However, these dimensions may be varied with the size ofthe valve constructions, pressures involved, etc.

In a mixing valve of this type, a restriction 17 is desirable in the hotwater inlet 10 to drop the pressure in the mixing chamber 11 so that thediaphragm modulating valve 14 will have sufficient pressure differentialto open, to admit cold water when required for mixing. When a fixedorifice is used in the hot water inlet 10, suitably sized for normal mixflows, the mix temperature increases materially when the mix flow isdecreased, as by partial closing of the downstream point of use faucetvalve 19. The rise of the mix temperature under these conditions, is dueto the appreciable increase in mix chamber pressure which results in adisproportionate decrease in cold water intake through thediaphragm-type modulating valve 14.

Use of a variable orifice of the type disclosed herein in the hot waterinlet 10 acts to provide a relatively more constant differential acrossthe modulating diaphragm valve 14 under varying flow rates of mix waterthan can be obtained with a fixed orifice. When the variable orifice isused, the orifice size increases for higher flow rates and decreases forlower flow rates. Thus, under lower flow rate conditions, as thevariable orifice reduces in size, the mix chamber pressure does notincrease to the same degree as when a fixed orifice is used. This actsto provide the diaphragm-type modulating valve 14 with a relativelyhigher pressure differential, allowing a more consistent proportion ofcold water intake at lower flow rates, so that mix temperatures at lowerflows do not rise to the same degree as when a fixed orifice is used.

The modulating action of the diaphragm 15 in combination with thelongitudinally adjustable pilot plunger 16 is particularly advantageouswhen the plunger 16 is held at a stationary adjusted position by rod 29.The plunger end 64 may be held at a cold water flow modulating position,as shown in FIG. 3, so that a relatively smooth modulated flow of coldwater flows from cold water inlet 13 to the mixing chamber 11. Thediaphragm 15 is not moved by the plunger 16 to a fully closed position,during the stationary adjustment of plunger 16 under the conditions ofFIG. 3 so that an improved modulated flow of cold water is obtained.

THE VARIABLE ORIFICES FIGS. 3-5 and 9-18 show variable orifices ororifice means according to this invention, and which automatically varythe aperture means to increase the size of the aperture directly with anincrease of flow rate, and vice versa.

In FIGS. 3-5 and 9-14, the rounded surface of the backing ring 54 on thedownstream side provides a limit of deflection of the orifice. Thiscontouring of the backing ring 54 predetermines the amount of opening ofthe orifice 18, etc., to produce characteristics of pressure drop vs.flow to suit the desired performance by the use of interchangeablebacking rings.

In FIG. 15 a flat spring biased blade is placed adjacent the inletorifice 112 to tend to close such orifice 112. The blade 110progressively opens the orifice 112 as the flow increases and viceversa, to provide a similar effect. This structure of FIG. 15 may beapplied to the hot water passageway of the valve construction of FIGS.1-8 or may be used in any other desired location. i

In FIG. 16 a.conical spring construction 116 may be placed adjacent theinlet 118 against shoulder 117 by ring 119. The helical spring 120progressively elongates and opens its in terstice construction as theflow increases, and vice versa, with substantially the same effect aspreviously described. The construction of FIG. 16 may be used inconnection with the hot water passageway of the valve construction ofFIGS. l-8 or may be used in any other desired location.

FIG. 17 shows a variable flexible orifice member 122 which may beslitted as in FIGS. 9, l0, l3 and 14 and is held by the contouredbacking ring 124 and retainer split ring 126 adjacent the fluid inlet128. The ring 124 may be contoured as described in connection withbacking ring 54. The construction of FIG. 17 may be used in the valveconstruction of FIGS. l-8 or elsewhere, as desired.

In FIG. 18, the flexible ring 130 may be slitted as in FIGS. 9, l0, l3and 14 and may have a stamped backing ring ahd clamping ring 132. Theouter rim 134 may be curled around the rim of the flexible ring 130. Thestructure may be held against the shoulder 136 by the split ring 138.The ring 130 may have a large central opening 140 to providesubstantially the same backing and flow characteristics as thepreviously described backing rings. The fluids enters at inlet I42 andis regulated as in previous flexible orifices. The structure of FIG. 18may be used with the hot water inlet of FIGS. 1 8 or el-- sewhere, asdesired.

FIG. 19 shows a remote control for the lever 29 of FIGS. I-3, etc. Thelever 29 is connected to the magnetic core which is located in theelectromagnetic coil 152. Energization of the coil 152 pulls the core orarmature I50 inwardly against the resistance of the tension spring 154to adjust the lever 29.

Any suitable remote control may be provided for the energization of thecoil 152. For example, a rheostat 156 may have a variable resistance 158connected to the coil 152 in any desired manner. For example, a contactlever 160, pivoted at 161, may sweep over the resistance 158 and producea variable current through the coil 152. The lever may may beelectrically connected by flexible wire 162 to the terminal 164 whichmay be connected by line 166 with a battery 168 and line 170 to the coil152. The lever may be adjusted by a manually or mechanically adjustablerod 172. A variable transformer, or the like, may be used variably toenergize the coil 152, if desired.

FIGS. 20 and 21 show a construction in which more than two fluid inletsare provided for the mixing chamber means 11A. A third source, or more,of fluid 25A, etc., may be added to the mixing valve construction ormeans 9A, which may otherwise be substantially the same as the mixingvalve construction 9 of FIG. 1. The source of fluid or conduit 25A maydischarge into the mixing chamber means 11A of FIG. 21, which mayotherwise be substantially the same as the mixing chamber 11 of FIG. 4.

A second diaphragm 15A may be added at the left side of FIG. 21 whichmay be symmetrical with the diaphragm 15 of FIG. 4. A third inlet means13A may receive fluid, if desired, from conduit 25A, and may have afluid passageway 39A leading from conduit 25A to the diaphragm 15A andthird inlet 32A into the mixing chamber 11A. The diaphragm 15A may becontrolled by proper pilot construction substantially identical to andsymmetrical with that of diaphragm 15, including a proper separatecontrol lever similar to and symmetrical with lever 29, etc. Sufficientparts of the additional structure added to FIG. 4 are indicated bysimilar reference numerals with suffixes A so that the parts can beidentified and their structure understood without further description.

The fluid entering from the conduit 25A may be cold water or any otherfluid, if desired.

Any further additional inlets may be added. The resilient variableorifice means 17 may be provided for the hot water inlet. Any otherinlet may be provided with a resilient variable inlet means, if desired.

FIG. 22 shows a construction in which the resilient variable orificemeans 17H (similar to orifice 17, etc.) may be installed in a bypassline or conduit 210 around an element 212, such as a tubular heatexchanger, to control a substantially constant flow through theexchanger with variations in the inlet supply pressure at inlet 214.Here the variable orifice 17H responds to increase and decrease insupply pressure to permit increased or decreased flow through the bypass210 with a minimum change of flow through the exchanger 212. In thisapplication, the exchange 212 acts as a fixed orifice in parallel withthe variable orifice 17H. The bypass 212 may discharge into the outlet216.

It is thus to be seen that fluid-mixing construction 9 has been providedincluding a first inlet means 10 with a source 24 of first fluid under afirst inlet pressure, a second inlet means 32 with a source 25 of secondfluid under a second inlet pressure, a mixing means 11 receiving andmixing said first fluid and second fluid and discharging such mixedfluids at outlet 12 at a lower mixed fluid discharge pressure with apressure difference relatively to said inlet pressures, and a resilientvariable orifice means, as shown in FIGS. 3-5 and 918 connected with one(10) of said inlets and increasing and decreasing the size of saidvariable orifice means in accordance with the increase and decrease insaid pressure difference. The resilient orifice means may be a resilientsheet means 17, 17A, 17B, 122 or 130 with a variable orifice l8 and thelike which increases in size with increasing flexure of said sheetmeans. A backing member 54, etc., is provided for said sheet means. Saidorifice means may be the spring member 120 of FIG. 16. A power operatedvalve is connected with the other (25) of said inlets, which power valveis a diaphragm valve with a pilot control means 16. One of the sourcesof fluid is from a heating means 22, both sources of fluid are sourcesof water, and the heating means 22 is a water heater and the sources ofwater are supplied from a single main (21) source of water, so that thesecond inlet pressure at inlet 25 is substantially the same as the inletpressure at inlet 10.

A third, or more, inlet means may also be provided.

Certain words may be used in this specification and/or the claimedsubject matter indicating direction, relative position, and the like.Such words are used for the sake of cleamess and brevity. However, suchwords are used only in connection with the views of the drawings, and inactual practice the parts so described may have entirely diflerentdirection, relative position and the like. Examples of such words may bevertical," horizontal, upper, lower," etc.

It is thus to be seen that an improved mixing valve construction, systemand method have been provided by this invention.

What is claimed is:

1. In combination, a valve construction having a cylindraceous hot waterinlet wall, a cylindraceous mixing chamber wall connected and alignedwith said hot water inlet wall, a cylindraceous mixed water outlet wallconnected to and aligned with said mixin chamber wall, a cylindraceouscold water inlet wall perpen icular to and supported by said mixingchamber wall, a fixed cold water diaphragm seat orifice wall formed insaid mixing chamber wall and connected in cold water flow relationshipto said cold water inlet wall and to said mixing chamber wall, saiddiaphragm seat orifice wall being surrounded by a diaphragm supportwall, said walls being homogeneously formed together, a diaphragm havinga pilot opening construction and a bleed opening construction, a pilotchamber means sealingly holding said diaphragm on said diaphragm supportwall construction, and a pilot plunger means reciprocable in said pilotchamber means toward and away from said pilot opening construction.

2. A combination according to claim 1 with said pilot chamber meanshaving a cylindraceous diaphragm engaging and sealing wall.

3. A combination according to claim 1 with said pilot chamber meanshaving a pilot plunger bearing means.

4. A combination according to claim 1 with said pilot chamber meanshaving a cylindraceous diaphragm engaging and sealing wall and having apilot plunger bearing means.

5. In combination, a valve construction having a cylindraceous firstfluid inlet wall, a cylindraceous mixing chamber wall connected andaligned with said first fluid inlet wall, a cylindraceous mixed fluidoutlet wall connected to and aligned with said mixing chamber wall, acylindraceous second fluid inlet wall perpendicular to and supported bysaid mixing chamber wall, a fixed second fluid diaphragm seat orificewall formed in said mixing chamber wall and connected in second fluidflow relationship to said second fluid inlet wall and to said mixingchamber wall, said diaphragm seat orifice wall being surrounded by adiaphragm support wall, said walls being homogeneously formed together,a diaphragm having a pilot opening construction and a bleed openingconstruction, a pilot chamber means sealingly holding said diaphragm onsaid diaphragm support wall construction, and a pilot plunger meansreciprocable in said pilot chamber means toward and away from said pilotopening construction.

1. In combination, a valve construction having a cylindraceous hot waterinlet wall, a cylindraceous mixing chamber wall connected and alignedwith said hot water inlet wall, a cylindraceous mixed water outlet wallconnected to and aligned with said mixing chamber wall, a cylindraceouscold water inlet wall perpendicular to and supported by said mixingchamber wall, a fixed cold water diaphragm seat orifice wall formed insaid mixing chamber wall and connected in cold water flow relationshipto said cold water inlet wall and to said mixing chamber wall, saiddiaphragm seat orifice wall being surrounded by a diaphragm supportwall, said walls being homogeneously formed together, a diaphragm havinga pilot opening construction and a bleed opening construction, a pilotchamber means sealingly holding said diaphragm on said diaphragm supportwall construction, and a pilot plunger means reciprocable in said pilotchamber means toward and away from said piLot opening construction.
 2. Acombination according to claim 1 with said pilot chamber means having acylindraceous diaphragm engaging and sealing wall.
 3. A combinationaccording to claim 1 with said pilot chamber means having a pilotplunger bearing means.
 4. A combination according to claim 1 with saidpilot chamber means having a cylindraceous diaphragm engaging andsealing wall and having a pilot plunger bearing means.
 5. Incombination, a valve construction having a cylindraceous first fluidinlet wall, a cylindraceous mixing chamber wall connected and alignedwith said first fluid inlet wall, a cylindraceous mixed fluid outletwall connected to and aligned with said mixing chamber wall, acylindraceous second fluid inlet wall perpendicular to and supported bysaid mixing chamber wall, a fixed second fluid diaphragm seat orificewall formed in said mixing chamber wall and connected in second fluidflow relationship to said second fluid inlet wall and to said mixingchamber wall, said diaphragm seat orifice wall being surrounded by adiaphragm support wall, said walls being homogeneously formed together,a diaphragm having a pilot opening construction and a bleed openingconstruction, a pilot chamber means sealingly holding said diaphragm onsaid diaphragm support wall construction, and a pilot plunger meansreciprocable in said pilot chamber means toward and away from said pilotopening construction.